L1
FAULT CODE
Ideal
Flow Overheat / No Water Flow Lockout
High Severity
Engineer Required
The boiler has locked out because the flow temperature is too high or no water is flowing.
Step-by-Step Fix Guide
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Step 1
Check the pressure gauge — if below 1 bar, repressurise using the filling loop
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Step 2
Bleed all radiators
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Step 3
Try a single reset
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Step 4 Engineer only
If the fault persists, a Gas Safe engineer should inspect the pump and temperature sensors
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.